There are 4 US Post Offices in Chase County serving a total of 2,413 residents equating to 603 residents per post office. It's estimated that approximately 3,851 packages are handled across the 4 county post offices annually. Chase County (county code CS) is a county located in the U.S. state of Kansas. As of the 2010 census, the county population was 2,790. Its county seat and most populous city is Cottonwood Falls. The center of population of Kansas is located in Chase County, about four miles north of Strong City."